Re: HELP! Corrupt attachments again
Can you provide more detail to what "corrupt" means in these cases? Which client software is being used for sending? Which encoding is being used? On Jan 22, 2008 4:14 PM, Oliver Marshall <[EMAIL PROTECTED]> wrote: > > > > > Hi chaps, > > We are still getting ongoing problems with attachments being corrupt. In a > group of about 15 people we see maybe two or three a day that get corrupted. > > As I've said before, im 100% certain it's not exchange as I can't find a > thing wrong, no error logs, no proof of corruption, no errors when running > isinteg etc, and nothing NOTHING is reproducible. At the moment I'm sending > two emails every 10 mins to a test account on the server, each email has two > attachments (pdf and jpg). So far I've opened and viewed the same > attachments 60 times and haven't found a thing wrong. > > My believe is that the attachments are getting corrupt before it hits their > network. Their .co.uk name goes through an ISPs mail sevrer where it's > filtering for spam and virus before being forward on. Their .COM goes > through a full email-store-and-forward type filtering service with another > provider. I've suggested that they get the ISPs to dump their mail in a pop > box, and have the exchange box collect them from there. Once done, if a user > has a problem, we can check the copy in the pop box and, if the attachment > is corrupt there as well, we know it's not their server. If it isn't corrupt > in the pop box, then, well, then I'm back to square one. > > Their connection is supplied by the serviced office company they lease from, > but while it's very well used, it doesn't show any packet loss indicative of > connections being dropped, so I'm inclined to rule this out. > > Has anyone got any other suggestions on how to bug hunt this ? > > > > Olly > > > > > > -- ME2 ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja~
RE: HELP! Corrupt attachments again
> My believe is that the attachments are getting corrupt before it hits > their network. Their .co.uk name goes through an ISPs mail sevrer > where it’s filtering for spam and virus before being forward on. It's likely virus/attachment filtering software that's mangling things. You'll need the help of the ISP to get to the bottom of it. As a stopgap try compressing all attachments with winrar. Most filters don't understand rar format and will pass them through. ~JasonG -- ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja~
RE: HELP! Corrupt attachments again
Emails come in from too many (too large) sources to have them all rar'd.
There's no AV on the exchange server, and having spoken to the ISP it's a
typically response ("no one else is having problems") and their logs don’t show
anything to them outta the norm (their AV logs don’t show any cock-ups).
The .COM name goes via a proper internet side AV and AS filtering service which
has a proper web based management interface with decent configuration options.
So far we haven’t had a problem with .COM attachments. HOWEVER they rarely use
the .COM at all and are slow to tell clients to use that instead.
Olly
-Original Message-
From: Jason Gurtz [mailto:[EMAIL PROTECTED]
Sent: 22 January 2008 21:36
To: MS-Exchange Admin Issues
Subject: RE: HELP! Corrupt attachments again
> My believe is that the attachments are getting corrupt before it hits
> their network. Their .co.uk name goes through an ISPs mail sevrer
> where it’s filtering for spam and virus before being forward on.
It's likely virus/attachment filtering software that's mangling things.
You'll need the help of the ISP to get to the bottom of it. As a stopgap
try compressing all attachments with winrar. Most filters don't
understand rar format and will pass them through.
~JasonG
--
~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~
~ http://www.sunbeltsoftware.com/Ninja~
~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~
~ http://www.sunbeltsoftware.com/Ninja~
Re: HELP! Corrupt attachments again
These messages that get corrupted - what do they look like on your
end? Any attachments? Any odd names?
On Jan 22, 2008 4:55 PM, Oliver Marshall <[EMAIL PROTECTED]> wrote:
> Emails come in from too many (too large) sources to have them all rar'd.
> There's no AV on the exchange server, and having spoken to the ISP it's a
> typically response ("no one else is having problems") and their logs don't
> show anything to them outta the norm (their AV logs don't show any cock-ups).
>
> The .COM name goes via a proper internet side AV and AS filtering service
> which has a proper web based management interface with decent configuration
> options. So far we haven't had a problem with .COM attachments. HOWEVER they
> rarely use the .COM at all and are slow to tell clients to use that instead.
>
> Olly
>
> -Original Message-
> From: Jason Gurtz [mailto:[EMAIL PROTECTED]
> Sent: 22 January 2008 21:36
> To: MS-Exchange Admin Issues
> Subject: RE: HELP! Corrupt attachments again
>
> > My believe is that the attachments are getting corrupt before it hits
> > their network. Their .co.uk name goes through an ISPs mail sevrer
> > where it's filtering for spam and virus before being forward on.
>
> It's likely virus/attachment filtering software that's mangling things.
> You'll need the help of the ISP to get to the bottom of it. As a stopgap
> try compressing all attachments with winrar. Most filters don't
> understand rar format and will pass them through.
>
> ~JasonG
>
> --
>
>
> ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~
> ~ http://www.sunbeltsoftware.com/Ninja~
>
> ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~
> ~ http://www.sunbeltsoftware.com/Ninja~
--
ME2
~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~
~ http://www.sunbeltsoftware.com/Ninja~
RE: HELP! Corrupt attachments again
" These messages that get corrupted - what do they look like on your end? Any attachments? Any odd names?" Nope, nothing. The file sizes are believable (don't know what they were before they were encoded) and aren't out of the realms of what you would expect. We have had the odd report of multiple people at this place receiving the same email with an attachment (all in the TO address) and one of them not being able to open the attachments. Is it possible that the email comes through to the server without problem, then gets corrupted when being downloaded/viewed in outlook (ie corruption occurs between the server and the client), and then the corrupted email gets punted back to the users mailbox ? I think im talking outta my bottom now. ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja~
Re: HELP! Corrupt attachments again
Have someone do an MD5 checksum on the file before sending it, and see if your receive it the same. On Jan 22, 2008 5:12 PM, Oliver Marshall <[EMAIL PROTECTED]> wrote: > Corrupt means, in the case of zip files, they refuse to open in any zip > package due to the archive being corrupt. Repairing them often recovers > *some* of the info. PDF files refuse to open, though in the latest Adobe > Reader you can open them but find that parts of pages are missing. JPG's > either fail to open or open and show only part of the image. Thats in > the case of the attachments that are 'corrupt'. > > Clients sending varies. We've had yahoo, gmail, outlook, Apple Mail as > the sender clients. > > As for headers, I only have access to the headers from one of the emails > in question. The details for the jpg part of the email are (i've had to > gnarl the strings to get the list server to allow this email through); > > Content - Type: image/jpeg; >Name = "Photo-0248_000.jpg" > Content - Transfer-Encoding: base64 > Content - Description: Photo-0248_000.jpg > Content - Disposition: attachment; >File name="Photo-0248_000.jpg" > > > > > ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ > ~ http://www.sunbeltsoftware.com/Ninja~ > -- ME2 ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja~
RE: HELP! Corrupt attachments again
Alas it's not *that* reproducible. I'm on 85 attachments so far tonight, and nothing yet. However, i'll quickly knock up a checksum on the file i'm sending now just incase it happens. Olly -Original Message- From: Micheal Espinola Jr [mailto:[EMAIL PROTECTED] Sent: 22 January 2008 22:15 To: MS-Exchange Admin Issues Subject: Re: HELP! Corrupt attachments again Have someone do an MD5 checksum on the file before sending it, and see if your receive it the same. On Jan 22, 2008 5:12 PM, Oliver Marshall <[EMAIL PROTECTED]> wrote: > Corrupt means, in the case of zip files, they refuse to open in any zip > package due to the archive being corrupt. Repairing them often recovers > *some* of the info. PDF files refuse to open, though in the latest Adobe > Reader you can open them but find that parts of pages are missing. JPG's > either fail to open or open and show only part of the image. Thats in > the case of the attachments that are 'corrupt'. > > Clients sending varies. We've had yahoo, gmail, outlook, Apple Mail as > the sender clients. > > As for headers, I only have access to the headers from one of the emails > in question. The details for the jpg part of the email are (i've had to > gnarl the strings to get the list server to allow this email through); > > Content - Type: image/jpeg; >Name = "Photo-0248_000.jpg" > Content - Transfer-Encoding: base64 > Content - Description: Photo-0248_000.jpg > Content - Disposition: attachment; >File name="Photo-0248_000.jpg" > > > > > ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ > ~ http://www.sunbeltsoftware.com/Ninja~ > -- ME2 ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja~ ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja~
RE: HELP! Corrupt attachments again
We ran into this where small attachments never had a problem. Start sending large attachments and it was reproducible. Ended up being a bad NIC at some level. Put a new NIC and the problem went away. Dell came out and swapped the system board and that fixed it permanently. From: Oliver Marshall [mailto:[EMAIL PROTECTED] Sent: Tuesday, January 22, 2008 4:14 PM To: MS-Exchange Admin Issues Subject: HELP! Corrupt attachments again Hi chaps, We are still getting ongoing problems with attachments being corrupt. In a group of about 15 people we see maybe two or three a day that get corrupted. As I've said before, im 100% certain it's not exchange as I can't find a thing wrong, no error logs, no proof of corruption, no errors when running isinteg etc, and nothing NOTHING is reproducible. At the moment I'm sending two emails every 10 mins to a test account on the server, each email has two attachments (pdf and jpg). So far I've opened and viewed the same attachments 60 times and haven't found a thing wrong. My believe is that the attachments are getting corrupt before it hits their network. Their .co.uk name goes through an ISPs mail sevrer where it's filtering for spam and virus before being forward on. Their .COM goes through a full email-store-and-forward type filtering service with another provider. I've suggested that they get the ISPs to dump their mail in a pop box, and have the exchange box collect them from there. Once done, if a user has a problem, we can check the copy in the pop box and, if the attachment is corrupt there as well, we know it's not their server. If it isn't corrupt in the pop box, then, well, then I'm back to square one. Their connection is supplied by the serviced office company they lease from, but while it's very well used, it doesn't show any packet loss indicative of connections being dropped, so I'm inclined to rule this out. Has anyone got any other suggestions on how to bug hunt this ? Olly ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja~
RE: HELP! Corrupt attachments again
I second the notion on the NIC. If you're using MB NICs, see if there's updated drivers, or put in a good Intel card or similar and try it again. BTDT. From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Tuesday, January 22, 2008 4:44 PM To: MS-Exchange Admin Issues Subject: RE: HELP! Corrupt attachments again We ran into this where small attachments never had a problem. Start sending large attachments and it was reproducible. Ended up being a bad NIC at some level. Put a new NIC and the problem went away. Dell came out and swapped the system board and that fixed it permanently. From: Oliver Marshall [mailto:[EMAIL PROTECTED] Sent: Tuesday, January 22, 2008 4:14 PM To: MS-Exchange Admin Issues Subject: HELP! Corrupt attachments again Hi chaps, We are still getting ongoing problems with attachments being corrupt. In a group of about 15 people we see maybe two or three a day that get corrupted. As I've said before, im 100% certain it's not exchange as I can't find a thing wrong, no error logs, no proof of corruption, no errors when running isinteg etc, and nothing NOTHING is reproducible. At the moment I'm sending two emails every 10 mins to a test account on the server, each email has two attachments (pdf and jpg). So far I've opened and viewed the same attachments 60 times and haven't found a thing wrong. My believe is that the attachments are getting corrupt before it hits their network. Their .co.uk name goes through an ISPs mail sevrer where it's filtering for spam and virus before being forward on. Their .COM goes through a full email-store-and-forward type filtering service with another provider. I've suggested that they get the ISPs to dump their mail in a pop box, and have the exchange box collect them from there. Once done, if a user has a problem, we can check the copy in the pop box and, if the attachment is corrupt there as well, we know it's not their server. If it isn't corrupt in the pop box, then, well, then I'm back to square one. Their connection is supplied by the serviced office company they lease from, but while it's very well used, it doesn't show any packet loss indicative of connections being dropped, so I'm inclined to rule this out. Has anyone got any other suggestions on how to bug hunt this ? Olly ___ The information contained in this E-mail message, including any attached files transmitted, is confidential and may be legally privileged. It is intended only for the sole use of the individual(s) named above. If you are the intended recipient, be aware that your use of any confidential or personal information may be restricted by state and federal privacy laws. If you, the reader of this message, are not the intended recipient, you are hereby notified that you should not further disseminate, distribute or forward this E-mail message. If you have received this E-mail in error, please notify the sender and delete the material from your computer system. This message is provided for information purposes and should not be construed as a solicitation or offer to buy or sell any securities or related financial instruments in any jurisdiction. ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja~
RE: HELP! Corrupt attachments again
We had a vaguely similar situation but with http downloads of .exe files through a cisco proxy. Our network folks said it only dropped a few packets during heavy load conditions and the next version might fix it. We started using FTP, external DSL connections etc. - the network folks have lots of power - not sure why. From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Tuesday, January 22, 2008 4:44 PM To: MS-Exchange Admin Issues Subject: RE: HELP! Corrupt attachments again We ran into this where small attachments never had a problem. Start sending large attachments and it was reproducible. Ended up being a bad NIC at some level. Put a new NIC and the problem went away. Dell came out and swapped the system board and that fixed it permanently. From: Oliver Marshall [mailto:[EMAIL PROTECTED] Sent: Tuesday, January 22, 2008 4:14 PM To: MS-Exchange Admin Issues Subject: HELP! Corrupt attachments again Hi chaps, We are still getting ongoing problems with attachments being corrupt. In a group of about 15 people we see maybe two or three a day that get corrupted. As I've said before, im 100% certain it's not exchange as I can't find a thing wrong, no error logs, no proof of corruption, no errors when running isinteg etc, and nothing NOTHING is reproducible. At the moment I'm sending two emails every 10 mins to a test account on the server, each email has two attachments (pdf and jpg). So far I've opened and viewed the same attachments 60 times and haven't found a thing wrong. My believe is that the attachments are getting corrupt before it hits their network. Their .co.uk name goes through an ISPs mail sevrer where it's filtering for spam and virus before being forward on. Their .COM goes through a full email-store-and-forward type filtering service with another provider. I've suggested that they get the ISPs to dump their mail in a pop box, and have the exchange box collect them from there. Once done, if a user has a problem, we can check the copy in the pop box and, if the attachment is corrupt there as well, we know it's not their server. If it isn't corrupt in the pop box, then, well, then I'm back to square one. Their connection is supplied by the serviced office company they lease from, but while it's very well used, it doesn't show any packet loss indicative of connections being dropped, so I'm inclined to rule this out. Has anyone got any other suggestions on how to bug hunt this ? Olly ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja~
Re: HELP! Corrupt attachments again
3rd'd considering the file size issue that Gary mentioned. Seen that before too. On Jan 22, 2008 7:53 PM, <[EMAIL PROTECTED]> wrote: > > > > > I second the notion on the NIC. If you're using MB NICs, see if there's > updated drivers, or put in a good Intel card or similar and try it again. > BTDT. > > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Tuesday, January 22, 2008 4:44 PM > > To: MS-Exchange Admin Issues > Subject: RE: HELP! Corrupt attachments again > > > > > > > > > > We ran into this where small attachments never had a problem. Start sending > large attachments and it was reproducible. Ended up being a bad NIC at some > level. Put a new NIC and the problem went away. Dell came out and swapped > the system board and that fixed it permanently. > > > > > > > > > > From: Oliver Marshall [mailto:[EMAIL PROTECTED] > Sent: Tuesday, January 22, 2008 4:14 PM > To: MS-Exchange Admin Issues > Subject: HELP! Corrupt attachments again > > > > > > Hi chaps, > > We are still getting ongoing problems with attachments being corrupt. In a > group of about 15 people we see maybe two or three a day that get corrupted. > > As I've said before, im 100% certain it's not exchange as I can't find a > thing wrong, no error logs, no proof of corruption, no errors when running > isinteg etc, and nothing NOTHING is reproducible. At the moment I'm sending > two emails every 10 mins to a test account on the server, each email has two > attachments (pdf and jpg). So far I've opened and viewed the same > attachments 60 times and haven't found a thing wrong. > > My believe is that the attachments are getting corrupt before it hits their > network. Their .co.uk name goes through an ISPs mail sevrer where it's > filtering for spam and virus before being forward on. Their .COM goes > through a full email-store-and-forward type filtering service with another > provider. I've suggested that they get the ISPs to dump their mail in a pop > box, and have the exchange box collect them from there. Once done, if a user > has a problem, we can check the copy in the pop box and, if the attachment > is corrupt there as well, we know it's not their server. If it isn't corrupt > in the pop box, then, well, then I'm back to square one. > > Their connection is supplied by the serviced office company they lease from, > but while it's very well used, it doesn't show any packet loss indicative of > connections being dropped, so I'm inclined to rule this out. > > Has anyone got any other suggestions on how to bug hunt this ? > > > > Olly > > > > > > > > > > > > > > __ > > The information contained in this E-mail message, including any attached > files transmitted, is confidential and may be legally privileged. It is > intended only for the sole use of the individual(s) named above. If you are > the intended recipient, be aware that your use of any confidential or > personal information may be restricted by state and federal privacy laws. If > you, the reader of this message, are not the intended recipient, you are > hereby notified that you should not further disseminate, distribute or > forward this E-mail message. If you have received this E-mail in error, > please notify the sender and delete the material from your computer system. > This message is provided for information purposes and should not be > construed as a solicitation or offer to buy or sell any securities or > related financial instruments in any jurisdiction. > > > > > -- ME2 ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja~
RE: HELP! Corrupt attachments again
I'll look to see whats on the server, however, i'm now at about 400 attachments that we have sent them, all ones that previously they have had problems with, and none of them are yet corrupt, so I'm not convinced its just a network card issue, unless it only happens at load. -Original Message- From: Micheal Espinola Jr [mailto:[EMAIL PROTECTED] Sent: 23 January 2008 06:07 To: MS-Exchange Admin Issues Subject: Re: HELP! Corrupt attachments again 3rd'd considering the file size issue that Gary mentioned. Seen that before too. On Jan 22, 2008 7:53 PM, <[EMAIL PROTECTED]> wrote: > > > > > I second the notion on the NIC. If you're using MB NICs, see if there's > updated drivers, or put in a good Intel card or similar and try it again. > BTDT. > > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Tuesday, January 22, 2008 4:44 PM > > To: MS-Exchange Admin Issues > Subject: RE: HELP! Corrupt attachments again > > > > > > > > > > We ran into this where small attachments never had a problem. Start sending > large attachments and it was reproducible. Ended up being a bad NIC at some > level. Put a new NIC and the problem went away. Dell came out and swapped > the system board and that fixed it permanently. > > > > > > > > > > From: Oliver Marshall [mailto:[EMAIL PROTECTED] > Sent: Tuesday, January 22, 2008 4:14 PM > To: MS-Exchange Admin Issues > Subject: HELP! Corrupt attachments again > > > > > > Hi chaps, > > We are still getting ongoing problems with attachments being corrupt. In a > group of about 15 people we see maybe two or three a day that get corrupted. > > As I've said before, im 100% certain it's not exchange as I can't find a > thing wrong, no error logs, no proof of corruption, no errors when running > isinteg etc, and nothing NOTHING is reproducible. At the moment I'm sending > two emails every 10 mins to a test account on the server, each email has two > attachments (pdf and jpg). So far I've opened and viewed the same > attachments 60 times and haven't found a thing wrong. > > My believe is that the attachments are getting corrupt before it hits their > network. Their .co.uk name goes through an ISPs mail sevrer where it's > filtering for spam and virus before being forward on. Their .COM goes > through a full email-store-and-forward type filtering service with another > provider. I've suggested that they get the ISPs to dump their mail in a pop > box, and have the exchange box collect them from there. Once done, if a user > has a problem, we can check the copy in the pop box and, if the attachment > is corrupt there as well, we know it's not their server. If it isn't corrupt > in the pop box, then, well, then I'm back to square one. > > Their connection is supplied by the serviced office company they lease from, > but while it's very well used, it doesn't show any packet loss indicative of > connections being dropped, so I'm inclined to rule this out. > > Has anyone got any other suggestions on how to bug hunt this ? > > > > Olly > > > > > > > > > > > > > > __ > > The information contained in this E-mail message, including any attached > files transmitted, is confidential and may be legally privileged. It is > intended only for the sole use of the individual(s) named above. If you are > the intended recipient, be aware that your use of any confidential or > personal information may be restricted by state and federal privacy laws. If > you, the reader of this message, are not the intended recipient, you are > hereby notified that you should not further disseminate, distribute or > forward this E-mail message. If you have received this E-mail in error, > please notify the sender and delete the material from your computer system. > This message is provided for information purposes and should not be > construed as a solicitation or offer to buy or sell any securities or > related financial instruments in any jurisdiction. > > > > > -- ME2 ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja~ ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja~
RE: HELP! Corrupt attachments again
> [...] and having spoken to the
> ISP it's a typically response ("no one else is having problems") and
> their logs don’t show anything to them outta the norm (their AV logs
> don’t show any cock-ups).
Unless you have access to the plain text logs and spool directories from
the A/V system at the ISP you cannot know that to be true. If you can
install a more capable mail client on each end (such as Thunderbird
perhaps) then you will have easy access to the plain text source of each
mail (via ctrl + u in TB client) and can inspect the source encoded mail
and destination copy more closely. Are the mime headers correct in terms
of offset. are things being truncated? "Helpful" line ending conversions
mussing things up? 7bit<->8bit conversion? If they refuse to work with
you, then you are likely up the proverbial creek since it is out of your
control. You will have to switch ISPs or bring all portions of the mail
system in-house (of which the latter is normally a better solution for all
but the smallest shops anyway IMO).
There's a *very* slight chance of a network problem being at fault. Cisco
devices have a feature that does deep inspection of certain protocols at
the application level. Unfortunately, "fixup protocol smtp" is buggy and
is known to cause mail deliverability problems though NOT usually ones
like you describe. In any case "no fixup protocol smtp" should be entered
into the config of any Cisco device between sender and receiver.
As other posters have noted, the various mail transport protocols have
long had built-in checks and balances to ensure proper delivery.
You can't do rar...pity. Can you have people password protect their zip
files/office docs?
~JasonG
--
~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~
~ http://www.sunbeltsoftware.com/Ninja~
RE: HELP! Corrupt attachments again
"Can you have people password protect their zip
files/office docs?"
Not really. We can advise the users to advise their various clients to rar the
files, but it's unlikely to happen.
Their .com uses a filtering service with access to the logs and much better
management, along with the ability to filter copies to pop3 accounts etc. In
all, I think we are drawing a line under it, taking a deep breath, and telling
the client that we advise them, going forward, to move both domains to a new
service with better tools.
Thanks for all the help with the advice. I'll let you know how much of my legs
they rip off !
-Original Message-
From: Jason Gurtz [mailto:[EMAIL PROTECTED]
Sent: 23 January 2008 15:15
To: MS-Exchange Admin Issues
Subject: RE: HELP! Corrupt attachments again
> [...] and having spoken to the
> ISP it's a typically response ("no one else is having problems") and
> their logs don’t show anything to them outta the norm (their AV logs
> don’t show any cock-ups).
Unless you have access to the plain text logs and spool directories from
the A/V system at the ISP you cannot know that to be true. If you can
install a more capable mail client on each end (such as Thunderbird
perhaps) then you will have easy access to the plain text source of each
mail (via ctrl + u in TB client) and can inspect the source encoded mail
and destination copy more closely. Are the mime headers correct in terms
of offset. are things being truncated? "Helpful" line ending conversions
mussing things up? 7bit<->8bit conversion? If they refuse to work with
you, then you are likely up the proverbial creek since it is out of your
control. You will have to switch ISPs or bring all portions of the mail
system in-house (of which the latter is normally a better solution for all
but the smallest shops anyway IMO).
There's a *very* slight chance of a network problem being at fault. Cisco
devices have a feature that does deep inspection of certain protocols at
the application level. Unfortunately, "fixup protocol smtp" is buggy and
is known to cause mail deliverability problems though NOT usually ones
like you describe. In any case "no fixup protocol smtp" should be entered
into the config of any Cisco device between sender and receiver.
As other posters have noted, the various mail transport protocols have
long had built-in checks and balances to ensure proper delivery.
You can't do rar...pity. Can you have people password protect their zip
files/office docs?
~JasonG
--
~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~
~ http://www.sunbeltsoftware.com/Ninja~
~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~
~ http://www.sunbeltsoftware.com/Ninja~
